The present invention relates to a paper machine for the manufacture of a multilayer paper web, and particularly, relates to a paper machine having several twin-wire formers.
Such a paper machine is known from U.S. Pat. No. 4,830,709, which discloses a paper machine for the manufacture of a multilayer paper web using two twin-wire formers. One embodiment shows two twin-wire paths which are formed by three wire loops, wherein the middle wire loop extends through both wire paths. Another embodiment shows a first twin-wire former having a long forwardly extending lower wire on which the paper web formed by the second twin-wire former is applied by the bottom wire of the second twin-wire former. The purpose of these embodiments is to provide a twin-wire former which permits the highest possible range of paper weights and wire speeds.
The embodiments in this prior patent have the disadvantage that one substantial requirement for paper webs is not satisfied, namely that the two surfaces of the multilayer paper web formed have properties which are as uniform as possible in view of the arrangement of the drainage elements.